When semiconductor chips are manufactured, lines along which a semiconductor substrate should be divided are processed in the semiconductor substrate by cutting or the like, and the substrate is bonded to a sheet. Furthermore, this sheet is stretched and expanded to apply stress to the semiconductor substrate in the direction of plane, and the substrate is thereby divided into semiconductor chips.
FIGS. 13A and 13B show a conventional manufacturing method of semiconductor chips C. FIG. 13A illustrates a state where a semiconductor substrate W is bonded to an extendable resin sheet S and the peripheral portion of the sheet S is supported by a frame F, and FIG. 13B illustrates a process in which the semiconductor substrate W is divided into the semiconductor chips C with a pushing machine M.
As illustrated in FIG. 13A, the semiconductor substrate W has semiconductor devices D (elements) formed over its substrate face, and lines L along which the substrate should be divided are processed by cutting or the like. Furthermore, a substrate face of the semiconductor substrate W on the back side is bonded to the extensible resin sheet S. A bonding layer B is formed over the entire face of the sheet S to which the semiconductor substrate W is to be bonded by applying ultraviolet curing adhesive or the like. The entire substrate face of the semiconductor substrate W on the back side is bonded to the bonding layer B. The peripheral portion of the sheet S is supported by the annular frame F.
As illustrated in FIG. 13B, the pushing machine M that is placed beneath the semiconductor substrate W and is moved up/down by a moving unit, not shown, is used to press the semiconductor substrate W from the back side of the sheet S so that it is plunged up. Thus, the sheet S is stretched in the direction of plane (the directions indicated by arrows F1 and F2 in the drawing). As a result, stress is applied to the semiconductor substrate W bonded to the sheet S in the direction of plane, and the semiconductor substrate W is divided into multiple semiconductor chips C (JP-A-2004-349456).
However, the conventional method for manufacturing semiconductor chips involves a problem. The stretch of the sheet S is restricted by the bonding layer B in the vicinity of lines L along which the substrate should be divided, and sufficient force cannot be sometimes applied to the lines L along which the substrate should be divided. That is, a semiconductor substrate W is not accurately divided, like the portion indicated by symbol X, and this lowers the yield of semiconductor chips C.
As indicated by symbol Y, powder from the bonding layer B expanded in conjunction with the stretch of the sheet S can fly in all directions when the semiconductor substrate W is divided, and it can stick to semiconductor devices D.